In a manufacturing process of an array substrate required by a display panel, signal-line conduction layers in different layers are usually connected through a via hole. For example: a drain electrode of a thin film transistor (hereinafter thin film transistor is short for TFT) disposed under an insulating layer and a pixel electrode disposed on the insulating layer are required to be connected, the insulating layer in the region where the drain electrode of the TFT overlaps the pixel electrode is usually provided with a via hole, and when the pixel electrode is formed, at the same time, a conductive connection portion having a same material as the pixel electrode is formed in the via hole, so that the drain electrode of the TFT and the pixel electrode are electrically connected through the conductive connection portion formed in the via hole.